BACnet B-EC Elevator Controller Profile

B-EC is the BACnet Elevator Controller profile (Annex L): what it is, where it's used, and the services an elevator controller must initiate and execute.

What B-EC Is

A BACnet device profile is a standardized capability level: a checklist of things a device must be able to do before it can wear the label. B-EC (BACnet Elevator Controller) is defined in Annex L of ANSI/ASHRAE 135-2024 (clause L.13.2) as a controllable view of an elevator or escalator group: it reports status, generates events, and accepts writes, unlike the read-only B-EM.

The checklist items are BACnet Interoperability Building Blocks (BIBBs). B-EC is a B-role device. A device documents its claim in its PICS (Protocol Implementation Conformance Statement); to verify a claim, ask for the PICS and check the profile line.

Where It’s Used

B-EC fits an elevator or escalator gateway that both reports status and accepts building-system commands.

  • Elevator group integration. A controller exposing car status and accepting service or recall commands from the building system.
  • Escalator control. A device reporting and controlling escalator run states over BACnet.
  • Lift dispatch integration. Surfacing a lift controller to a BMS that both watches and issues commands.

Required Services

The table below is the exhaustive service set required by the B-EC BIBBs. Initiates means the device sends the request or notification; Executes means the device receives and acts on it (responding, for confirmed services). BIBB codes encode the same split: a -A BIBB is the initiating side, a -B BIBB the executing side. A - means the profile does not require that direction; a device may still support it.

Capability areaServiceRequired by BIBBInitiatesExecutes
Data sharingReadPropertyDS-RP-B-Yes
Data sharingReadPropertyMultipleDS-RPM-B-Yes
Data sharingWritePropertyDS-WP-B-Yes
Data sharingWritePropertyMultipleDS-WPM-B-Yes
Data sharingSubscribeCOVDS-COV-B-Yes
Data sharingConfirmedCOVNotificationDS-COV-BYes-
Data sharingUnconfirmedCOVNotificationDS-COV-BYes-
Data sharingSubscribeCOVPropertyMultipleDS-COVM-B-Yes
Data sharingConfirmedCOVNotificationMultipleDS-COVM-BYes-
Data sharingUnconfirmedCOVNotificationMultipleDS-COVM-BYes-
Alarm and event managementConfirmedEventNotificationAE-N-I-BYes-
Alarm and event managementUnconfirmedEventNotificationAE-N-I-BYes-
Alarm and event managementAcknowledgeAlarmAE-ACK-B-Yes
Alarm and event managementGetEventInformationAE-INFO-B-Yes
Device and network managementWho-IsDM-DDB-A, DM-DDB-BYesYes
Device and network managementI-AmDM-DDB-A, DM-DDB-BYesYes
Device and network managementWho-HasDM-DOB-B-Yes
Device and network managementI-HaveDM-DOB-BYes-
Device and network managementDeviceCommunicationControlDM-DCC-B-Yes
Device and network managementTimeSynchronization ¹DM-TS-B-Yes
Device and network managementUTCTimeSynchronization ¹DM-UTC-B-Yes
Device and network managementReinitializeDeviceDM-RD-B-Yes

The elevator equipment is modeled as hosted objects. The device presents its cars and escalators through Lift and Escalator objects.

¹ The profile requires one of the two time-synchronization services, not both. (Protocol_Revision is a readable property of the device’s Device object.)

ProfileHow it differs from B-EC
B-EMElevator Monitor: read-only, no write or time-synchronization requirement
B-AECAdvanced Elevator Controller: adds an event log, internal scheduling, and backup and restore
B-EWSElevator Workstation: the operator-side profile that displays and commands these devices

What Chipkin Provides

The CAS BACnet Stack implements the BIBB set the B-EC profile requires, including the Lift and Escalator object model, event generation, and change-of-value reporting. Talk to us about building or integrating a B-EC device on the stack.